1. Field of the Invention
The present invention relates to a backlight unit driver, and more particularly, to a backlight unit driver capable of driving multi-channel lamps of a backlight unit, especially light emitting diode lamps, by supplying a driving power to the lamps using a single transformer and maintaining the current balance of the driving power supplied to each of the lamps.
2. Description of the Related Art
In recent years, flat panel display (FPD) devices, reflecting the user's demand for high resolution, large-sized screens and the like, have been replacing display devices using a cathode ray tube (CRT) in the display industry.
Particularly, in the case of a large-sized display device, a Liquid Crystal Display (LCD) device has shown rapid growth due to advantages such as a smaller-size and a lighter-weight in comparison to other display devices, and such an LCD device is being expected to grow in prominence henceforth, in view of price and marketability.
Meanwhile, a Cold Cathode Fluorescent Lamp (CCFL) has been used as a backlight light source in a conventional LCD device. In recent years, however, the use of a Light Emitting Diode (LED) lamp has been gradually increased due to various advantages including power consumption, life span and environmentally friendly characteristics.
In the case that such an LED lamp is used as a backlight light source of an LCD device, the constant current control of the LED lamp in each channel should be ensured in order to guarantee uniformity of brightness throughout the entirety of a screen.
To enable this, each LED lamp according to the related art employs a direct current-direct current (DC-DC) converter, in which the DC-DC converter converts an input DC power into a driving power and supplies the converted power to the LED lamp, so that the current flowing through each LED lamp may be precisely controlled. In this case, however, as many DC-DC converters and controllers are required as the number of LED lamps. This leads to problems such as an increase in production costs as well as in the volume of an LED lamp driver, and a reduction in power conversion efficiency because of the plurality of DC-DC converters as well as in reliability because of an active element, an integrated circuit or the like applied to the DC-DC converters.